fix(ci): fix release builds for linux-aarch64 and windows-x86_64

linux-aarch64: Install protoc v25.1 binary in Cross.toml pre-build
(apt protobuf-compiler is too old for proto3 optional labels). Pass
PROTOC env var through to cross container.

windows-x86_64: Set CFLAGS=/MD and CXXFLAGS=/MD to force dynamic CRT
linkage for all C/C++ dependencies. Fixes LNK2038 mismatch between
esaxx-rs (/MT static) and cxx (/MD dynamic).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: RichardHightower

.github/workflows/release.yml

@@ -78,6 +78,10 @@ jobs:
         shell: bash
         run: |
           echo "LIBCLANG_PATH=C:\\Program Files\\LLVM\\lib" >> $GITHUB_ENV
+          # Force dynamic CRT (/MD) for all C/C++ deps to prevent LNK2038 mismatch
+          # (esaxx-rs defaults to /MT which conflicts with cxx's /MD)
+          echo "CFLAGS=/MD" >> $GITHUB_ENV
+          echo "CXXFLAGS=/MD" >> $GITHUB_ENV
 
       - name: Disable usearch simsimd for cross-compile targets
         if: matrix.cross || runner.os == 'Windows'
@@ -112,6 +116,7 @@ jobs:
           PKG_CONFIG_ALLOW_CROSS: "1"
           PKG_CONFIG_PATH: /usr/lib/aarch64-linux-gnu/pkgconfig
           PKG_CONFIG_SYSROOT_DIR: /
+          PROTOC: /usr/local/bin/protoc
         run: cross build --release --target ${{ matrix.target }}
 
       - name: Create archive directory

Cross.toml

@@ -2,7 +2,8 @@
 pre-build = [
     "dpkg --add-architecture arm64",
     "apt-get update",
-    "apt-get install -y protobuf-compiler libclang-dev libssl-dev:arm64 pkg-config"
+    "apt-get install -y libclang-dev libssl-dev:arm64 pkg-config curl unzip",
+    "curl -LO https://github.com/protocolbuffers/protobuf/releases/download/v25.1/protoc-25.1-linux-x86_64.zip && unzip protoc-25.1-linux-x86_64.zip -d /usr/local && rm protoc-25.1-linux-x86_64.zip"
 ]
 
 [target.aarch64-unknown-linux-gnu.env]
@@ -13,6 +14,7 @@ passthrough = [
     "PKG_CONFIG_ALLOW_CROSS",
     "PKG_CONFIG_PATH",
     "PKG_CONFIG_SYSROOT_DIR",
+    "PROTOC",
 ]
 
 [build.env]